Ireland, the UK officially became the United Kingdom of Great Britain and Northern Ireland. From 1580 to 1640, Portugal was under a united monarchy with Spain, in the period known as the Iberian Union. Between 1867 and 1890 Luxembourg and the Netherlands shared the same monarch. Charles III currently reigns over 15 Commonwealth realms. The King of France was also the co-prince of Andorra. After the abolition of the French monarchy the co-prince is now the president of the French Republic. See also List of former monarchies List of current monarchies List of current monarchs of sovereign states Non-sovereign Monarchy References